沥青面层松散探地雷达波场响应特征研究

Study on wave field characteristics of GPR to loose asphalt mixture

沥青混凝土材料松散是常见的道路面层典型病害,会引发路面网裂、坑槽等早期病害,影响道路的使用性能和寿命.依据沥青混凝土的多相、离散和随机分布统计特征,应用量化约束多相离散随机介质建模方法,构建了不同空隙率的沥青混凝土材料松散病害模型并进行探地雷达正演模拟,研究松散对应的探地雷达波场特征及其直观诊断方法.研究结果表明:与传统的层状均匀介质模型相比,多相离散随机介质模型可以更准确的描述沥青混凝土材料松散病害的真实状态,其数值模拟结果更符合实测雷达数据;沥青混凝土材料松散程度越大,介质非均匀性越明显,其对应的探地雷达波振幅越强,波形越杂乱,区域振幅曲线变化越剧烈,两侧的绕射波越明显.根据探地雷达的波形杂乱程度、振幅强度和变化剧烈程度,能够更直观、准确的定位沥青混凝土材料松散区域,定性对比沥青混凝土的松散程度,为采取针对性的处治修复措施提供依据.

Loose asphalt concrete is a commonly encountered defect in road surface layers,often leading to premature issues such as pavement cracking and potholes,thereby compromising the overall performance and lifespan of the road.Leveraging the statistical characteristics of asphalt concrete's multiphase,discrete,and random distribution,we employed a quantitative constraint multiphase discrete random medium modeling approach to develop models of asphalt concrete loosening with varying porosity rates.Additionally,we conducted GPR(Ground Penetrating Radar)forward modeling to investigate the GPR wavefield characteristics and intuitive diagnostic techniques associated with loosening.Our research findings reveal that,in comparison to traditional layered uniform medium models,the multiphase discrete random medium model offers a more precise portrayal of the actual state of asphalt concrete loosening.Furthermore,its numerical simulation outcomes align more closely with measured radar data.As the degree of asphalt concrete loosening increases,the inhomogeneity of the medium becomes more evident,resulting in a stronger amplitude of the corresponding GPR wave,a more chaotic waveform,more intense variations in regional amplitude curves,and more prominent diffraction waves on both sides.By analyzing the GPR waveform chaos,amplitude intensity,and intensity of change,we can more intuitively and accurately identify loose areas in asphalt concrete,qualitatively assess the degree of loosening,and provide a solid foundation for targeted treatment and repair measures.